Thermostatic steam trap



Dec. 16, 1947.

l. VAN ZWIENEN THERIOSTATIG STEAK TRAP Filed Jan. 24, 1945 uvvmrox;1729c l an Zuyienen .v of a one-pipe gravity Patented Dec. 16, 1941UNITED STATES PATENT OFFICE I "rinuuuos'r li 'i r o s rnliri'rlml I IngeVan Zwlenen, Brooklyn, N. Y.

' Application January 24,

12 Olalms. (cl-23H) The invention relates generally to heating systemsand particularly to certain features of improvement which,'while.capableof being applied to serve various purposes, are specially adapted,

as herein embodied, for use with the radiators return system, tocooperate with manually or thermostatically controlled steam supplyvalves, .to maintain the radiators in eilective operation desiredtemperature. The improvement may be readily applied tosuch a heatingsystem, without requiring material change therein and will result inconverting it, in eifect, into a two-pipe system,

with all the well known'accompanylng advantages.

More specifically, the invention resides essentially in a highlyefilcient thermostatically operated trap, for automatically effectingthe required drainage of radiators to prevent the accumulation ofcondensate therein and the resulting disadvantages.

Prominent among the importantfeatures of the invention may be mentionedthe following: first, a drainage trap located in the live steamconnection but in non-interfering relation to the maintenance tors, thetrap having a valved opening at the top for the entrance of live steam,to effect equalization of pressure between the trap and the supply lineand a valved opening at the bottom for the discharge of the trappedcondensate; second, a thermostatic control valve for the trap, whichconsists, preferably, of a diaphragm-sun' I ported bellows type ofthermostat, having valves at opposite ends, which, under flexing of thediaphragm and contraction and expansion or the bellows, act to open andclose the trap at the upper-and lower ends; third, the provision ofmeans for automatically effecting, practically instantaneously, anequalization of the high pressure in the trap and the low pressure ofthe condensate in the radiator, as the cally closed by the thermostaticvalves, which permits instant flow of condensate into the trap, as thehead of the accumulated condensate in the radiator is suilicient, underthe condition of balanced pressures, to force and open a check valvecontrolling a communicating passage; fourth,

'the provision of perforations in the diaphragm that supports thethermostat in the trap, communication between the trap and below thediaphragm and fifth, the provision of an air vent in the condensateconnection adjacent to the trap.

Other features of the invention not specially for free of a full steamsupply to the radi'atrap isperiodichambers above for producing heat atany" use is bent down g5 shownin Fi 3,

.edge being shown, for

near the top thereof. A suitable valves ll, ll, formed inpart 194s,set-mm 574,291

mentioned above, will be brought to attention in the detaileddescription that follows;

A preferred embodiment of the invention is illustrated in theaccompanying drawing but I do not wish to be understood as intending tolimit myself to either the form or details shown, as various changes maybe made t in without departing from the spirit and scope of theinvention as outlined in the appended claims.

In-the drawings: I

Fig. 1 is a view in elevation showing a radiator connected in a one-pipeheating system, with my invention applied.

Fig. 2 is. a vertical section on an enlarged scale, of a thermostatictrap unit, constructed in accordance with my invention.

Fig. 3 is a view in elevation, partly in sectio showing a slightlymodified construction.

Fig. 4 is a detail'plan view of the diaphragm shown in Fix. 2. theprojection from the outer clearness of illustration, the plane oi thediaphragm but in at right angles to the same. Fig. 5 is a similar viewof the diaphragm partly extending in Fig. 6 is a detail cross section,on the line s -s of Fig.2 and Fig. '7 is a horizontal section, on theline s' -s of Fig, 2.

Referring now to the drawings, 1 represents a well known type ofradiator such as is now in common use. 2 indicates a live steam pipefrom a boiler ,(not shown) connected to supply the radiator and also toserve as a return for condensation from the same, as is customary inone-pipe heating systems.

Instead of the usual radiator valve, a casing I is interposed in thelive steam and drainage connections of the radiator and provides anvopen unobstructed connecting passage 4 between pipe 2 and an upwardextension 5 from the casing 3, that is connected to the radiator at apoint I modulating or thermostatic valve I is provided in the upwardextension '5, by which the supply of live to the radiator may beregulated for any desired pressure. Q I

A trap 8, within the casing of condensation rrom the radiator to thelive steam pipe 2, by which it is returned to the boiler. The trap isprovided with a bottom opening 9 and a top opening it, both leading tothe live steam passage 4 in the casing and botn controlled by by the exansion and contraction or a thermostat steam V 3, controls the flow withand operated i2. The thermostat is carried and supported by a diaphragmI 3, seated to have limited vertical movement in an annular groove itformed between the trap casing proper l5 and a removable screw cap I6.The diaphragm has a number of openings formed therein, as indicated atll, to provide free communication between the trap chambers above andbelow the diaphragm.

In operation, the expansion of the thermostat causes the valves to closethe trap opening 8, first and secondly trap opening against the entrancetherein of live steam. on initial contraction, the upper valve is firstwithdrawn from the opening l0, permitting live steam to enter the trapand effect equalization of pressure between the trap and the live steamsupply. 0n continued contraction of the thermostat, the lower valve iswithdrawn from the opening 9, permitting drainage of the condensate fromthe trap to the live steam line. Live steam-which replaces th condensatein the trap, heats and expands the thermostat to complete the cycle.

The flow of condensation from the drainage connection I! of the radiatorto the trap, is through a connecting passage l8, controlled by a checkvalve H! of either the ball or gate type, as shown. Directly below thepassage is and communicating with it through one or more narrowslot-like openings i 8 there is a mud pit I8 for the deposit andaccumulation of foreign matter carried by the drainage, Overflow fromthe pit enters the trap through one or more openings Iii and a screwplug I8 provides access to the pit for cleaning. The valve I 9 opens topermit the flow to the trap only when the trap is closed and thepressure in the trap and the pressure in the drainage connection of theradiator are equalized. To eil'ect such an equalization of thesepressures, a vent 20 is provided in the 'wall between the trap andthedrainage connection, which may be either valved as indicated at 2i inFig. 2, or open, as shown in Fig. 3. When a valve is employed in thevent, it is arranged to Open when the trap is closed and close when thetrap is open. A spring 22 is accordingly used to close the valve and adownwardly projecting lug 23 fromthe diaphragm, acts, by having its freeend moved outward somewhat by the flexing of the diaphragm and theexpansion of the thermostat, to draw the valve from its seat and hold itthus with the vent open until the thermostat contracts and opens thetrap.

A well known form tion, as indicated at 24, the radiator, as indicatedat 25.

. permitting such flow,

From the foregoing, it will be seen that the radiators are individuallycontrolled and maintained at the highest point of heating efficiency byaction of the traps, which are automatic in operation and require noadjustment or other attention.

When a radiator is shut oil by closing the steam regulating valve 1 thetrap is so designed as to prevent the flow of live steam through thetrap into the radiator through the drainage connection.

Upon opening the valve 1, to start up a cold radiator, live steamentering the same will be instantly condensed, causing more or lessaccumulation of water therein, which flows by gravity through thedrainage connection into the trap. the equalization of pressure throughthe vent 20,

which will continue until the thermostat contracts sumciently under theaction 01' the low temperature condensation, to open the trap andthereupon the water in the trap will be discharged by gravity into thelive steam pipe 2 and returned to the boiler. The trap remains open onlylong enough for live steam to enter and expand the thermostatsufliciently to close it and the above described cycle will beperiodically repeated as long as steam is supplied.

to the radiator.

The above described combination of trap and modulating valve, wheninstalled on all radiators of a one-pipe gravity return system, enablesany desired temperature to be maintained.

I claim: r

1. An automatic drainage trap comprising a casing provided with livesteam supply and trap.

2. A drainage trap, as defined in claim 1, in which there is anunobstructed passage through the casing for live steam that by-passesthe trap.

3. An automatic drainage trap comprising a casing provided with livesteam supply and drainage connections, a drainage trap within the casingopening at its upper and lower ends into the live steam supplyconnection, valves controlling the aforesaid trap openings, a thermostatin the trap for imparting operating movement in opposite directions tothe valves to open and close the same, the said thermostat acting whencontracted of condensate in the trap.

. 4. A drainage trap, as defined in claim 3, in which there is an openpassage through the casing for live steam that partly surrounds andby-passes the trap.

-5. An. automatic drainage trap comprising a casing provided with livesteam supply and drainage connections, a drainage trap within the casingopening at its upper and lower ends into the live steam supplyconnection, valves controlling the aforesaid trap openings, a thermostatin the trap for imparting operating movement in opposite open and closethe same, a diaphragm supporting the thermostat and dividing theinterior of the tra into upper and lower chambers and means providingcontinuous communication between'the chambers.

6. An automatic drainage trap comprising a casing provided with livesteam supply and drainage connections, a drainage trap within the casingopening at its upper and lower ends into the live steam supplyconnection, valves controlling the aforesaid trap openings, a thermostatin the trap for imparting operating movement in opposite directions tothe valves to open and close the same, and an apertured diaphragmmounted in i the trap adjacent to the upper valved opening thereof, thesaid diaphragm supporting the thermostat and dividing the trap intoupper and lower chambers opening one into the other through theapertures in the diaphragm;

7. g A drainage trap. as defined in which the drainage connection to thetrap is controlled by a valve adapted to yield and admit oon-. densateto the trap when the pressure in the trap and in .the drainageconnection are equalized.

8. A drainage trap, as defined in claim It, in which the drainageconnection to the trap is controlled by a. pressure-closed check valveadapted to 1% opened by the head of the accumulated claim 1, in

to the live steam supply connection, a one-way pressure operated valvein the passage between the trap and the drainage connection controllingthe drainage flow into the trap and a vent through which pressure isequalized between th trap and the drainage connection when the trap isclosed, a thermostatic valve operative between said axially aligned topand bottom openings for opening and closing the trap, the saidthermostatic valve opening the trap when contracted to dischargeaccumulated condensation into the live steam supply connection andadmitlive steam to the trap to expand the valve and close the trap, and

' an open unobstructed passage through the casing condensate in thedrainage connection to admit the condensate to the trap when thepressure in the trap is not in excess of that in the drainageconnection.

9. A drainage trap, as defined in claim 1, in

which an air vent is provided in the drainage connection adjacent to thetrap.

10. A drainage trap, as defined in claim 1, in which a valved air ventis provided in the drainage connection adjacent to the trap.

11. An automatic drainage trap comprising a casing provided with livesteam supply and drainage connections, a drainage trap within the casinghaving axially ings therein, said bottom sage for drainage from openingproviding a pasthe drainage connection for live steam, thatby-passes thetrap.

12. A drainage'trap, which the vent, through which pressureis-equaliz'ed between the trap and the drainage connection, iscontrolled by. a valve that is-automatically 20'opened when thethermostatic valve is expanded to close the trap.

INGE VAN 'ZWIENEN.

I REFERENCES CITED 2 The 'following referencesare of record in thealigned top and bottom openfile of this patent:.

' STATES PATENTS UNITED Number Name Date 1,884,857 Randall Oct. 25, 19322,028,173

Thomas Jan. 21, 1936 as defined in claim 11, in

